The pre-election economic and fiscal update the Treasury releases on Tuesday week will have to reflect a darker view of the economic outlook than the upbeat document it delivered on Budget day.
The Budget was predicated on the view that, after a nasty dose of recession, the economy was coming right and the Government could afford to focus on structural issues such as cutting its spending as a share of GDP.
World growth had recovered, underpinning the most favourable terms of trade (mix of export and import prices) for decades and boosting national income.
The mammoth task of rebuilding Christchurch awaited a construction sector starved of work.
And highly stimulatory monetary policy could be expected to work its magic on household consumption, via a recovering housing market and other channels.
By now, the Budget said, we would be looking at an economy set to expand by 4 per cent over the next 12 months.
Not so. The global economy, in particular, did not get the memo.
Consensus forecasts for growth among New Zealand's trading partners have been revised down and down.
They are now expected to grow 3 per cent this year and 3.9 per cent next year, compared with a forecast of 3.7 per cent and 4.4 per cent respectively at Budget time.
It is not just that the economies of Europe and the United States are faltering while their political leaders seem incapable of doing anything except make things worse. Recently forecasts for emerging Asian economies have been downgraded too, recognising they are not immune from doings in their Western markets.
And past experience suggests that when things are heading rapidly south consensus forecasts tend to lag reality.
Export commodity prices, although still high by historical standards, have been generally falling for months.
Combined with elevated levels of risk aversion in global financial markets, this has taken some pressure off the exchange rate, but on a trade-weighted basis the dollar is still 3 per cent stronger than the Budget forecasts assumed it would be at this stage.
Perhaps the clearest indicator that investors are taking a very gloomy view of the outlook for growth is the global slump in bond yields.
In New Zealand's case that has pulled 10-year bond yields back to where they were by the end of the recession in early 2009.
And remember it was uncertainty about the global outlook and the heightened risk that our export-led recovery will be sideswiped by an international shock that led governor Alan Bollard to defer the interest rate hike he had signalled for last month.
Indeed the markets now think it will be the September quarter next year before the official cash rate rises from its current all-time low.
On the home front estimates of the cost of the seismic calamity in Canterbury keep rising, even as ongoing aftershocks delay rebuilding.
The reconstruction of Christchurch will start later, take longer and cost more than expected at Budget time. It will boost activity but it is, of course, not the kind of growth you want, as it only replaces wealth destroyed.
As for domestic demand in the rest of the economy, the Treasury seems to be taking a positive view, to judge by its monthly commentaries on the economic data flow.
"It is important to emphasise that the weaker global environment will not be the only factor influencing the forecasts," says its most recent report.
"These forecasts will need to balance the partially offsetting factors of stronger momentum in domestic demand, the weaker global outlook, and what looks to be a larger but delayed Canterbury rebuild."
It is evidently impressed that the consumer has proven more resilient than it expected, with real private consumption growing 0.3 per cent in the June quarter, following a 0.5 per cent increase in the March quarter.
But it is in fact a slower run rate for this indicator than last year and in the second half of 2009 - a period which businesses are unlikely to look back on fondly as one of rip-roaring growth.
Worse, the most recent indicators suggest even that momentum is fading.
The value of retail sales charged to electronic cards, normally 60 per cent of total retail spending, rose 0.5 per cent in the September quarter compared with the June quarter, seasonally adjusted. But the June quarter had been up 2.2 per cent on the March quarter, which in turn was 2.5 per cent up on the December quarter last year.
Housing market indicators remain mixed. The Real Estate Institute said yesterday that sales last month were down 2.3 per cent on August, seasonally adjusted. Turnover has fallen in three of the past four months.
Its house price index is up 2.7 per cent on a year ago, but still 3 per cent below its peak in December 2007.
In the year to August the stock of mortgage debt grew just 1.3 per cent, half the increase of the year before, as households take advantage of the lowest mortgage rates in decades to repay principal, rather than trade up and gear up.
The net inflow of migrants has dwindled to a meagre and exiguous trickle, just 2300 in the year ended August, compared with a long-run average of 12,000.
A torpid labour market constrains wage growth. The unemployment rate at 6.5 per cent is exactly in line with its average over the previous eight quarters.
Finally, NZIER's quarterly survey of business opinion indicated trading conditions in the September quarter were flat and consistent with an economy growing at the same annual rate as in the June quarter, just 1.5 per cent.
All in all, not a lot of self-propelled growth is occurring to counter the effects of the global economy veering from tailwind to headwind.
Meanwhile the Crown accounts for the June 2011 year, released on Tuesday, show how much the Government's financial position has deteriorated from what was expected at the time of the May Budget.
The commonest measure of the fiscal deficit, the operating balance excluding gains and losses, came in at $18.4 billion compared with the Budget's already eye-watering $16.7 billion.
That reflected an extra $3 billion hit to the Earthquake Commission, wiping it out financially.
The accounts also revealed that last year's tax package was far from being revenue neutral, at least in its first nine months. The revenue forgone through tax cuts exceeded the increased tax take from the higher GST rate by $1.1 billion.
At the same time Government spending not related to the earthquakes increased by $4.5 billion.
The net effect was a timely boost to demand from fiscal policy.
But this year's Budget, by contrast, was a "zero" Budget that froze operating spending. The Government has foreshadowed more of the same, its resolve no doubt stiffened by having its credit rating downgraded.
So with households in the grip of a newfound prudence, the Government fixated on returning to surplus, and global growth slowing sharply, where is the growth to come from?
A lot of the bumper Fonterra payout will be spent, of course, and eventually the rebuilding of Christchurch will get under way.
But on balance the pre-election forecasts should be more Cassandra than Pollyanna.